Lokkaite-(Y) is a rare yttrium-rich carbonate mineral typically occurring as thin, platy crystals or fine-grained aggregates in pegmatitic environments. It is a secondary mineral formed through the alteration of other yttrium-bearing minerals, often appearing as coatings or encrustations on host rock surfaces.

Hardness

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrare

Lokkaite-(Y)

Hardness: 3
Luster: Pearly
Streak: White
Transparency: Translucent

Is this lokkaite-(y)?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch lokkaite-(y) with a known reference. Lokkaite-(Y) sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lokkaite-(Y) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lokkaite-(Y) typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: white, yellowish, colorless.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: platy crystals, aggregates, crusts.

Often confused with

Lokkaite-(Y) vs. its common look-alikes — and how to tell them apart in the field.

mineral

Tengerite-(Y)

Mohs 3.5

How to tell apart: Luster reads pearly on Lokkaite-(Y) and dull on Tengerite-(Y).

How to tell apart: Luster reads pearly on Lokkaite-(Y) and vitreous on Calcite.

Compare →

Often found alongside lokkaite-(y)

Minerals reported to co-occur with lokkaite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: CaY₄(CO₃)₇·9H₂O
Mohs hardness: 3
Density: 3.37 g/cm³
Colors: White Yellowish Colorless
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Platy Crystals, Aggregates, Crusts
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find lokkaite-(y)

Classic worldwide localities

Lokka, Finland
Ytterby, Sweden
Kola Peninsula, Russia

Field-hunting tip

Look in granite pegmatites country — that is the host setting where lokkaite-(y) typically forms. If you start seeing bastnäsite, synchysite, quartz in float, you are in the right ground. Field specimens usually show a platy crystals, aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lokkaite-(y)?+

Mohs hardness is 3. It typically shows a pearly luster. The streak is white. Common colors include white, yellowish, colorless.

Where is lokkaite-(y) found?+

Notable localities include Lokka, Finland; Ytterby, Sweden; Kola Peninsula, Russia.

How much is lokkaite-(y) worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is lokkaite-(y) safe to handle?+

This mineral is radioactive. Contains rare earth elements and is radioactive; handle with care and wash hands after contact to prevent ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like lokkaite-(y)?+

Lokkaite-(Y) is most often confused with Tengerite-(Y), Calcite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with lokkaite-(y)?+

Lokkaite-(Y) commonly co-occurs with Bastnäsite, Synchysite, Quartz, Microcline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lokkaite-(y) form in?+

Lokkaite-(Y) typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lokkaite-(y) used for?+

Lokkaite-(Y) is used in collector.

Find lokkaite-(y) on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.